In Patent Literature 1, there has been proposed a resin molded article of a structure in which an insert component (included component) is insert molded by a thermosetting resin composition including a thermoplastic resin mixed therein. In the resin molded article, the mixed component in the thermosetting resin composition, which includes the thermoplastic resin mixed therein, is dispersed at the surface of the insert component in order to relax the stress at the interface between the thermosetting resin composition and the insert component. Specifically, the insert component is heated during molding, thereby to cause a temperature gradient. Using the temperature gradient, the formation of the continuous phase and the flocculated phase in the synthetic resin of the thermoplastic resin and the thermosetting resin, in other words, the formation of the sea-island structure is controlled. Namely, at the position away from the interface with the insert component, the phase structure in the synthetic resin is configured such that the thermoplastic resin forms a continuous phase (a so-called sea structure), and the thermosetting resin forms a flocculated phase (a so-called island structure). Whereas, at the interface with the insert component, the phase structure in the synthetic resin includes the thermoplastic resin as a flocculated phase and the thermosetting resin as a continuous phase.
As described above, since the insert component is heated during the molding, at a portion which is desired to be bonded with the insert component, the synthetic resin is made to have a phase structure in which the thermoplastic resin forms a flocculated phase, and the thermosetting resin forms a continuous phase.
Note that the flocculated phase herein referred to means the phase separated while having a definite interface between it and the continuous phase, or, in other words, can be referred to as a separate phase.